What Is an Appetite Suppressant?

Appetite suppressants are drugs that work on the brain to fool it into thinking that it is not hungry. They act primarily on the neurochemical transmitters of the central nervous system to reduce appetite and hunger to reduce food intake. Prescription appetite suppressants may be used in addition to a healthful diet and increased physical activity to achieve and maintain significant weight loss.

While some are intended for short-term use, others are meant to be used long-term. In addition to prescription medications, there are over-the-counter and "natural" supplement products available that claim to help suppress appetite and help you lose weight.

What Is an Appetite Suppressant?

Generally, the term "appetite suppressant" refers to a prescription medication that helps you to feel less hungry so that you eat less and lose weight. But the term is also used by some herbal and natural diet pill makers to describe plant-based, nonprescription products that aim to curb hunger.

You may see appetite suppressants advertised in magazines or online. While appetite suppressants may help some lose weight, they may not work for everyone. There are many reasons people maintain or gain weight, and the amount of food you eat is just one factor.

How Do They Work?

Appetite suppressants work in several ways. Some suppressants make you feel less hungry or full sooner, whereas others make it difficult for your body to absorb dietary fat. However, neither prescription nor natural appetite suppressants are a replacement for certain lifestyle changes to achieve weight loss.

According to a systematic and clinical review of long-term drug use for obesity treatment, medications resulted in a greater average weight loss than the placebos when combined with lifestyle interventions.

Diet and lifestyle changes can be challenging to make, which is why many people opt for a dietary supplement as a means of weight loss. However, experts concur that consuming a healthy diet and maintaining regular physical activity is the basis for long-term weight loss.

Precautions

Before starting any appetite suppressant—prescription or over-the-counter—discuss with your doctor any underlying medical diagnoses, previous medical emergencies, current medications, and general concerns that could interfere with the suppressant.

Certain prescription appetite suppressants caution use among people with heart disease, high or uncontrolled blood pressure, glaucoma, a history of eating disorders, or hyperthyroidism.

Side Effects and Risks

Appetite suppressants aren't without risk. Side effects vary from medication to medication and are often mild. However, some cases can be more severe, so it's important to speak with your doctor if adverse reactions persist.

The most common side effects associated with prescription and natural appetite suppressants include:

• Constipation
• Cough
• Diarrhea
• Dizziness
• Dry mouth
• Headaches
• Increased blood pressure
• Increased heart rate
• Insomnia/trouble sleeping
• Liver Damage
• Nausea
• Raised Pulse

Some medications may also increase the risk of suicidal thoughts or interact poorly in those with depression or other severe mental health conditions.

Prescription Appetite Suppressants

There are several FDA-approved medications for weight loss. Many of these weight loss medications are appetite suppressants and help promote weight loss by targeting hunger. These weight loss aids are available only with a prescription.

Belviq 

Belviq (lorcaserin) works to control appetite and metabolism by activating serotonin receptors that regulate hunger. By helping to control your appetite, Belviq may help you feel full after you've eaten less food. It is available by prescription to people with a body mass index (BMI) of 30 or a body mass index of 27 along with a weight-related condition.

Contrave 

Contrave is an extended-release combination of two FDA-approved medications: naltrexone hydrochloride and bupropion hydrochloride. It affects the central nervous system to reduce your appetite and curb cravings. The weight loss medication is prescribed along with a reduced-calorie diet and exercise program to help people lose weight.

Phentermine

Known by many brand names (including Adipex-P, Lomaira, and Suprenza), phentermine is one of the oldest medications for weight loss. Phentermine's side effects include increased blood pressure and heart rate, sleeplessness, and nervousness.

Qsymia 

Qsymia (phentermine and topiramate) is an extended-release capsule that suppresses appetite and, by extension, reduces your food intake. If you have a BMI over 30 or a body mass index of 27 and higher along with a weight-related condition, your doctor may prescribe this product. The medication needs to be taken along with lifestyle modifications for sustained weight loss.

Saxenda 

Saxenda (liraglutide [rDNA origin] injection) is an injectable medicine that helps people to feel full sooner so that they eat less and lose weight. Saxenda can be used by people with obesity (defined as having a BMI of 30 or more) or by people who have a BMI of 27 or more and a weight-related medical condition such as type 2 diabetes, high cholesterol, or high blood pressure.

Wegovy

Wegovy (Semaglutide) is a once-weekly injection for chronic weight management that was approved by the FDA. Semaglutide is a GLP-1 receptor agonist and has been previously approved for type 2 diabetes, under the names Ozempic (injection) and Rybelsus (oral tablets). 

Wegovy can be used by those with a starting body mass index (BMI) of greater than 30 (obesity) or greater than 27 (overweight) with a minimum of one weight-related condition such as hypertension, type 2 diabetes mellitus, or dyslipidemia.

Plenity

Plenity is an FDA approved device that functions similarly to an appetite suppressant or anti-obesity medicine. Gel particles combine with ingested food, inducing a larger volume in the stomach and small intestine. This higher elasticity and viscosity in the stomach and small intestine creates feelings of fullness and meal satiety, reducing hunger and thereby potentially decreasing calorie intake.

Plenity is approved for weight management for adults who have a body mass index (BMI) of 25 to 40 with excess weight or obesity. It should be combined with a healthy diet and exercise.

Natural Appetite Suppressants

Some products are available online and in health food stores, pharmacies, and vitamin shops that claim to be natural appetite suppressants. Fiber, for example, helps you to feel full longer after you eat. For this reason, some fiber supplement makers call it a natural appetite suppressant. 

Supplements are not tested, reviewed, or approved for safety and effectiveness by the FDA. If you're considering an herbal product to curb your hunger, be sure to gather all the facts before you buy it. You may even want to talk to your physician or pharmacist before you buy one, or some, of them. Some products are expensive and may not be as effective as you'd like them to be.

The following are some of the most popular natural appetite suppressants.

Fenugreek

Fenugreek is a Mediterranean herb with seeds that smell and taste like maple syrup. The ground-up seeds and extracts are used in cooking, spice mixes, medicines, and cosmetic products.

Fiber can act as a natural appetite suppressant by prolonging satiety, and fenugreek seeds are rich in fiber. A 2015 study also found that drinking fenugreek tea compared to a placebo led to a higher feeling of fullness in women who were overweight.

Fenugreek is considered safe in amounts typically found in food, but its safety in large doses is unknown. There are some potential side effects, namely diarrhea, nausea, and digestive tract symptoms. Fenugreek can also cause allergic reactions in some people. In very rare cases, fenugreek can cause dizziness and headaches. People taking it alone and in combination with other herbs have reported some cases of liver toxicity.

Glucomannan

Extracted from the root of the konjac plant, glucomannan is full of soluble fiber. It is said to help increase satiety and prolong the time it takes food to leave the stomach. Several clinical trials have evaluated glucomannan, but the effects on weight loss have been inconsistent.

Taking glucomannan isn't without risks. In the short term, it appears only to have minor side effects such as burping, bloating, loose stools, abdominal discomfort, gas, diarrhea, and constipation. However, not much is known about glucomannan's long-term safety. In the mid-1980s, tablet forms were associated with esophageal obstruction (though powdered and capsule forms were not).

Green Tea and Green Tea Extract

Caffeine and catechins are the two active components of green tea associated with weight loss. Many studies have sought to test whether green tea and its components produce a reduction in body weight, specifically through increased energy expenditure, fat oxidation, decreased fat absorption, and reduced lipogenesis.

The studies concluded that there might potentially be a modest effect on weight loss, but the effect would be small and not clinically relevant. There have been no studies directly investigating whether green tea or green tea extract function as appetite suppressants.

While there have been no adverse effects reported from drinking green tea, there is evidence that green tea extract may cause liver damage, particularly when taken on an empty stomach.

Garcinia Cambogia

Garcinia cambogia is a fruit tree found in Asia, Africa, and the Polynesian islands. The rind of the tree's fruit contains high levels of hydroxycitric acid (HCA). HCA is thought to suppress food intake and reduce weight gain. While studies with rats have found this to be true, evidence that garcinia cambogia works in humans is conflicting. If there is an effect, it's relatively minor.

Garcinia cambogia and HCA tend to have mild side effects, including headache, nausea, gastrointestinal issues, and upper respiratory tract symptoms. However, its long-term safety is not known.

Some people who have taken supplements containing garcinia cambogia had cases of liver toxicity, but garcinia cambogia could not be directly implicated as the supplements contained additional ingredients.

A Word From Verywell

If you are considering taking an appetite suppressant or think it might help you lose weight, be sure to consult your physician first. They are the best judge of whether an appetite suppressant is right for you and can work with you to determine the best ways to achieve your weight loss goals.